I have been having an issues for some time now when it comes to selection objects in particular linestrings. It started when I went to 5.x. What is happening is that when objects are to close together or on top of each other and you try to select one or more items and the list pops up asking you which items to select I will select the object from the list but it won't actually select the object. I have to go through the process two to three times in order get the linestring or strings selected. Is any one else having this issue? I am running windows 10 and so I wonder if that could be part of it.